Apparatuses and methods for coordinating operations between circuit switched (cs) and packet switched (ps) services with different subscriber identity cards, and machine-readable storage medium

ABSTRACT

A wireless communications device includes a radio frequency (RF) module and a baseband chip. The baseband chip is configured to initiate a mobile originated (MO) call through the RF module with a first subscriber identity card when the RF module is occupied by performing a packet switched (PS) data service with a second subscriber identity card, arbitrate a first protocol stack handler to suspend or terminate the PS data service associated with the second subscriber identity card in response to initiating the MO call associated with the first subscriber identity card, and arbitrate a second protocol stack handler to make the MO call associated with the first subscriber identity card when the PS data service associated with the second subscriber identity card is suspended or terminated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of pending U.S. patent applicationSer. No. 12/909,234, filed on Oct. 21, 2010, which claims the benefit ofU.S. Provisional Application No. 61/334,198, filed on May 13, 2010, theentirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention generally relates to the coordination of operationsbetween communication services, and more particularly, to thecoordination of the operations between CS and PS services with differentsubscriber identity cards.

Description of the Related Art

With growing demand for ubiquitous computing and networking, variouswireless communication technologies have been developed, such as theGlobal System for Mobile communications (GSM) technology, General PacketRadio Service (GPRS) technology, Enhanced Data rates for GlobalEvolution (EDGE) technology, Wideband Code Division Multiple Access(W-CDMA) technology, Code Division Multiple Access 2000 (CDMA 2000)technology, Time Division-Synchronous Code Division Multiple Access(TD-SCDMA) technology, Worldwide Interoperability for Microwave Access(WiMAX) technology, Long Term Evolution (LTE) technology, Time-DivisionLTE (TD-LTE) technology, and others. Generally, a cellular phone onlysupports one wireless communication technology and provides the user theflexibility of mobile communications at all times via the supportedwireless communication technology, regardless of his/her geographiclocation. Especially in today's business world, a cellular phone isbecoming a necessary business tool for conducting business conveniently.For business people, having an additional cellular phone exclusive forbusiness matters is a common choice, since they need to conduct businesswhile out of the office or even out of the city/country. Others may findhaving an additional cellular phone is a good way to save/control thebudget for wireless service charges (including phone services and/ordata services). However, having two or more than two cellular phones maybe troublesome when one has to switch frequently between the cellularphones and carry around all the cellular phones with himself/herself. Inorder to provide a convenient way of having multiple subscriber numbers,dual-card cellular phones have been developed, which generally have twowireless communications modules for respectively performing wirelesstransmission and reception with an individual subscriber number. Thedual-card design allows both wireless communications modules to beactive simultaneously and allows calls to be received on eithersubscriber numbers associated with one of the wireless communicationsmodules at any time. Thus, a dual-card cellular phone may be used forbusiness and personal use with separate subscriber numbers and bills, orfor travel with the second subscriber number for the country visited.

For the dual-card cellular phones with one single transceiver, only onewireless communications module is allowed to obtain network resourcesusing the single transceiver, while the other wireless communicationsmodule has no control over the single transceiver. Specially, thewireless communications module with no control over the singletransceiver is not aware that the single transceiver is occupied by theother wireless communications module, because the two wirelesscommunications modules operate independently and lack a propercommunication mechanism there-between. For example, a dual-card cellularphone may be configured such that the single transceiver is occupied bythe first wireless communications module for performing a data service,e.g. the Multimedia Messaging Service (MMS). When a Mobile Originated(MO) call for the second wireless communications module is requested bya user, an error message, such as “Network Failed”, may be shown on thescreen of the dual-card cellular phone since the second wirelesscommunications module has no access to the single transceiver, nor hasshown information about the statuses of the first wirelesscommunications module and the single transceiver.

Therefore, it is desirable to have a flexible way of managing theoperations between the multiple wireless communications modules formultiple subscriber identity cards, so that the operations of themultiple wireless communications modules may be coordinated to respondto users' MO requests.

BRIEF SUMMARY OF THE INVENTION

Accordingly, embodiments of the invention provide apparatuses andmethods for coordinating the operations between CS and PS services witha respective subscriber identity card. In one aspect of the invention, awireless communications device includes a radio frequency (RF) moduleand a baseband chip. The baseband chip is configured to initiate amobile originated (MO) call through the RF module with a firstsubscriber identity card when the RF module is occupied by performing apacket switched (PS) data service with a second subscriber identitycard, arbitrate a first protocol stack handler to suspend or terminatethe PS data service associated with the second subscriber identity cardin response to initiating the MO call associated with the firstsubscriber identity card, and arbitrate a second protocol stack handlerto make the MO call associated with the first subscriber identity cardwhen the PS data service associated with the second subscriber identitycard is suspended or terminated.

In another aspect of the invention, a method coordinates operationsbetween circuit switched (CS) and packet switched (PS) services withdifferent subscriber identity cards in a wireless communications device.The method comprises initiating a Mobile Originated (MO) call through aRF module from the wireless communications device with a firstsubscriber identity card when the RF module is occupied by performing aPS data service with a second subscriber identity card; determiningwhether the MO call has a higher priority than the PS data service;arbitrating a first protocol stack handler to suspend or terminate thePS data service associated with the second subscriber identity card inresponse to initiating the MO call associated with the first subscriberidentity card when the MO call has a higher priority than the PS dataservice; and arbitrating a second protocol stack handler to make the MOcall associated with the first subscriber identity card when the PS dataservice associated with the second subscriber identity card is suspendedor terminated.

In another aspect of the invention, a wireless communications devicecomprises a radio frequency (RF) module and a baseband chip. Thebaseband chip is configured to initiate a mobile originated (MO) callthrough the RF module from the wireless communications device with afirst subscriber identity card when the RF module is occupied byperforming a packet switched (PS) data service with a second subscriberidentity card, redirect the MO call to the second subscriber identitycard, and make the MO call with the second subscriber identity card. Thebaseband chip further determines whether the MO call has a higherpriority than the PS data service and the redirection of the MO call tothe second subscriber identity card is performed when the MO call has ahigher priority than the PS data service.

Other aspects and features of the present invention will become apparentto those with ordinarily skill in the art upon review of the followingdescriptions of specific embodiments of the apparatuses and methods forcoordinating the operations between CS and PS services with a respectivesubscriber identity card, and the machine-readable storage medium forstoring program code which performs the methods when executed.

BRIEF DESCRIPTION OF DRAWINGS

The invention can be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 is a block diagram of a wireless communications environmentaccording to an embodiment of the invention;

FIG. 2 shows an exemplary Call Control (CC) in a GSM system;

FIG. 3 shows a PDP context activation procedure initialized by an MS ina GPRS system;

FIG. 4 shows an exemplary uplink channel allocation in a GPRS system;

FIG. 5 shows an exemplary paging procedure of a SIM card of an MS in aGPRS system;

FIG. 6 is a block diagram illustrating the hardware architecture of anMS according to an embodiment of the invention;

FIG. 7 is a block diagram illustrating the hardware architecture of anMS according to another embodiment of the invention;

FIG. 8 is a block diagram illustrating the hardware architecture of anMS coupled with two subscriber identity cards and a single antennaaccording to an embodiment of the invention;

FIG. 9 is a block diagram illustrating the software architecture of anMS according to an embodiment of the invention;

FIG. 10 is a flow chart illustrating an embodiment of the method forcoordinating the operations between the protocol stack handlers 910 and920 with respect to the software architecture shown in FIG. 9;

FIG. 11 is a message sequence chart illustrating the method forcoordinating the operations between the protocol stack handlers 910 and920 according to the embodiment of FIG. 10;

FIG. 12 is a flow chart illustrating another embodiment of the methodfor coordinating the operations between the protocol stack handlers 910and 920 with respect to the software architecture shown in FIG. 9;

FIG. 13 is a block diagram illustrating the software architecture of anMS according to another embodiment of the invention;

FIG. 14 is a flow chart illustrating an embodiment of the method forcoordinating the operations between the protocol stack handlers 910 and920 with respect to the software architecture shown in FIG. 13;

FIG. 15 is a message sequence chart illustrating the coordination of theoperations between the protocol handlers 910 and 920 according to theembodiment of FIG. 14;

FIG. 16 is a block diagram illustrating the software architecture of anMS according to yet another embodiment of the invention;

FIG. 17 is a flow chart illustrating an embodiment of the method forcoordinating the operations between the protocol stack handlers 910 and920 with respect to the software architecture shown in FIG. 16; and

FIG. 18 is a message sequence chart illustrating the coordination of theoperations between the protocol handlers 910 and 920 according to theembodiment of FIG. 17.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best-contemplated mode of carryingout the invention. This description is made for the purpose ofillustrating the general principles of the invention and should not betaken in a limiting sense. It should be understood that the embodimentsmay be realized in software, hardware, firmware, or any combinationthereof.

FIG. 1 is a block diagram of a wireless communications environmentaccording to an embodiment of the invention. The wireless communicationsenvironment 100 comprises a mobile station (MS) 110, service networks120 and 130. The MS 110 may wirelessly communicate with the servicenetworks 120 and 130 with two separate subscriber numbers, after campingon two cells. The cell may be may be managed by a node-B, a base station(BS), an advanced BS (ABS), an enhanced BS (EBS) or others. However, thecommunication is only allowed to be performed with either one of theservice networks 120 and 130 at a given time. The service networks 120and 130 may be in compliance with any two of the GSM/GPRS/EDGE, WCDMA,CDMA 2000, TD-SCDMA, WiMAX, LTE, and TD-LTE technologies. The subscribernumbers may be provided by two separate subscriber identity cards incompliance with the specifications of the technologies employed by theservice networks 120 and 130. For example, the service network 120 maybe a GSM/GPRS/EDGE system, and correspondingly, one of the subscriberidentity cards may be a Subscriber Identity Module (SIM) card, while theservice network 130 may be a WCDMA, LTE, or TD-LTE system andcorrespondingly, the other one of the subscriber identity cards may be aUniversal SIM (USIM) card. Alternatively, the service network 120 may bea CDMA 2000 system and correspondingly, one of the subscriber identitycards may be a Removable User Identity Module (R-UIM) card, while theservice network 130 may be a TD-SCDMA system and correspondingly, theother one of the subscriber identity cards may be a CDMA subscriberIdentity Module (CSIM) card.

The MS 110 wirelessly access Internet resources, such as e-mailtransmission, Web browsing, file upload/download, instant messaging,streaming video, voice over IP (VOIP) or others, or making a wirelessphone call. In addition, a computer host or a notebook mayconnect/couple to the MS 110 and wirelessly access Internet resourcestherethrough. The MS 110 may be operated in idle mode or dedicated mode,in GSM systems, for the inserted SIM card. In idle mode, the MS searchesfor or measures the Broadcast Control Channel (BCCH) with better signalquality from a cell provided by a specific service network, or issynchronized to the BCCH of a specific cell and ready to perform arandom access procedure on the Random Access Channel (RACH) forrequesting a dedicated channel. In dedicated mode, the MS 110 occupies aphysical channel and tries to synchronize therewith, and establisheslogical channels and switches them through. Similarly, as the MS 110equipped with one or more USIM cards, the MS 110 may be operated in idlemode and connected mode, in the WCDMA or TD-SCDMA network, for eachinserted USIM card.

Taking a GSM system for example, referring to FIG. 2, Call Control (CC)comprising procedures to establish, control, and terminate calls is oneof the entities of Connection Management (CM). If there is an attempt tomake a call from an MS, i.e. Mobile Originated (MO) call, the CC entityfirst requests a Mobility Management (MM) connection from the local MMentity. For a simple call, the MS have to be registered with the GSMservice network, whereas the registration is only optionally requiredwith an emergency call. That is, an emergency call is also establishedon an unenciphered Radio Resource (RR) connection from an unregisteredMS. After successful establishment of this MM connection and activationof the user data encryption, the service-requesting CC entity isinformed. The MS signals on this connection the attempt to connect tothe CC entity in the Mobile Switching Center MSC (SETUP). The MSC mayrespond to this connection request in several ways. The Network Controland Management (MSC) may indicate with a CALL PROCEEDING message thatthe call request has been accepted and that all the necessaryinformation for the setup of the call is available. Otherwise, the callrequest may be declined with a RELEASE COMPLETE message. As soon as thecalled party accepts the call request (i.e. the corresponding node ofthe MS or a wired telephone), the MS receives an ALERTING message. Also,once the called party accepts the call, a CONNECT message which isacknowledged with a CONNECT ACKNOWLEDGE message is returned, and thus,switching through the call and the associated user data connection. Inaddition, CC in GSM systems has a number of peculiarities, especially toaccount for the limited resources and properties of the radio channel.In particular, the call request of the MS may be entered into a queue(call queuing), if there is no immediately free Traffic Channel (TCH)for the establishment of the call. The maximum waiting time a call mayhave to wait for assignment of a TCH can be adjusted according tooperator requirements. Furthermore, the point at which the TCH isactually assigned is chosen. For example, the TCH can be assignedimmediately after acknowledging the call request (CALL PROCEEDINGmessage), also referred to as early assignment. On the other hand, thecall may be first processed completely and the assignment occurs onlyafter the targeted subscriber is being called, also referred to as lateassignment or Off-Air Call Setup (OACSU). The OACSU may avoidunnecessary allocation of TCH if the called party is not available.Also, there is a probability that after a successful call requestsignaling procedure, no TCH may be allocated for the calling partybefore the called party accepts the call; and thus, the call cannot becompletely switched through and have to be broken off. CC of WCDMA orTD-SCDMA systems is similar to that of the GSM systems and is omittedherein for brevity.

MO short message service (SMS) messages are transported from an MS to aShort Message Service Centre (SMSC), and may be destined to mobileusers, subscribers on a fixed network, or Value-Added Service Providers(VASPs), also known as application-terminated. Mobile-terminated (MT)SMS messages are transported from the SMSC to the destination MS. In aGSM system, a completely established MM connection is required for thetransport of SMS messages, which again presumes an existing RRconnection with LAPDm protection on an SDCCH or SACCH. An SMS transportProtocol Data Unit (PDU) is transmitted with an RP-DATA message betweenMSC and MS using the Short Message Relay Protocol (SM-RP). Correctreception is acknowledged with an RP-ACK message either from the SMSservice center (mobile-originated SMS transfer). In WCDMA or TD-SCDMAsystems, before transport of SMS messages, a Radio Resource Control(RRC) connection has to be successfully established.

For the GPRS systems, networks based on the Internet Protocol (IP) (e.g.the global Internet or private/corporate intranets) and X.25 networksare supported. Before one of (U)SIM cards of an MS can use the GPRSservice, the MS needs to perform a GPRS attach procedure to attach tothe GPRS network with one (U)SIM card. In the GPRS attach procedure, theMS first sends an ATTACH REQUEST message to a Serving GPRS Support Node(SGSN). The GPRS network then checks if the MS is authorized, copies theuser profile from the Home Location Register (HLR) to the SGSN, andassigns a Packet Temporary Mobile Subscriber Identity (P-TMSI) to theMS. To exchange data packets with external Public Data Networks (PDNs)after a successful GPRS attach procedure, the MS applies for an addressused in the PDN, wherein the address is called a Packet Data Protocol(PDP) address. In the case where the PDN is an IP network, the PDPaddress is an IP address. For each session, a so-called PDP context iscreated, which describes the characteristics of the session. The PDPcontext describes PDP type (e.g. IPv4, IPv6 or others), the PDP addressassigned to the MS, the requested Quality of Service (QoS) class and theaddress of a Gateway GPRS Support Node (GGSN) that serves as the accesspoint to the external network. FIG. 3 shows the PDP context activationprocedure initialized by an MS. With the ACTIVATE PDP CONTEXT REQUESTmessage, the MS informs the SGSN of the requested PDP context. Afterthat, the typical GSM security functions (e.g. authentication of the MS)are performed. If the access is granted, the SGSN will send a CREATE PDPCONTEXT REQUEST message to the affected GGSN. The GGSN creates a newentry in its PDP context table, which enables the GGSN to route datapackets between the SGSN and the external PDN. The GGSN confirms therequest to the SGSN with a CREATE PDP CONTEXT RESPONSE message. Finally,the SGSN updates its PDP context table and confirms the activation ofthe new PDP context to the MS with an ACTIVATE PDP CONTEXT ACCEPTmessage. Note that for an MS using both CS and PS services, it ispossible to perform a combined GPRS/IMSI attach procedure. Thedisconnection from the GPRS network is called GPRS detachment, which maybe initiated by the MS or by the GPRS network.

In addition, IP packets are transmitted encapsulated within the GPRSbackbone network. The transmission is achieved using the GPRS TunnelingProtocol (GTP), that is, GTP packets carry the user's IP packets. TheGTP is defined both between GPRS Supports Nodes (GSNs) within the samePLMN and between GSNs of different PLMNs. It contains procedures in thetransmission plane as well as in the signaling plane. In thetransmission plane, the GTP employs a tunnel mechanism to transfer userdata packets. In the signaling plane, the GTP specifies a tunnel controland management protocol. The signaling is used to create, modify, anddelete tunnels. A Tunnel Identifier (TID), which is composed of the IMSIof the (U)SIM card and a Network Layer Service Access Point Identifier(NSAPI) uniquely indicates a PDP context. Below the GTP, a transmissioncontrol protocol (TCP) is employed to transport the GTP packets withinthe backbone network. In the network layer, IP is employed to route thepackets through the backbone. Taking the GSM systems for example, afterthe MS successfully attaches to a GPRS network with a (U)SIM card, acell supporting GPRS may allocate physical channels for GPRS traffic. Inother words, the radio resources of a cell are shared by the MS with the(U)SIM card.

FIG. 4 shows an exemplary uplink channel allocation (mobile originatedpacket transfer). The attached SIM card of the MS requests a channel bysending a PACKET CHANNEL REQUEST message on the Packet Random AccessChannel (PRACH) or RACH. The BSS answers on the Packet Access GrantChannel (PAGCH) or AGCH. Once the PACKET CHANNEL REQUEST message issuccessfully sent, a so-called Temporary Block Flow (TBF) isestablished. With the TBF, resources (e.g. Packet Data Traffic Channel(PDTCH) and buffers) are allocated for the attached (U)SIM card of theMS, and data transmission can start. During transfer, the Uplink StateFlag (USF) in the header of downlink blocks indicates to other MSs thatthis uplink PDTCH is already in use. On the receiver side, a TemporaryFlow Identifier (TFI) facilitates to reassemble the packet. Once alldata has been transmitted, the TBF and the resources are released.

FIG. 5 shows an exemplary paging procedure of a SIM card of a MS (mobileterminated packet transfer). The BSS pages the attached SIM card of theMS by sending a PACKET PAGING REQUEST message on the Packet PagingChannel (PPCH) or PCH. Correspondingly, the attached SIM card of the MSanswers on the Packet Random Access Channel (PRACH) or RACH.

FIG. 6 is a block diagram illustrating the hardware architecture of anMS according to an embodiment of the invention. The MS 600 is equippedwith a Baseband chip 610, and a single RF module 620 coupled with anantenna 630. The Baseband chip 610 may contain multiple hardware devicesto perform baseband signal processing, including analog to digitalconversion (ADC)/digital to analog conversion (DAC), gain adjusting,modulation/demodulation, encoding/decoding, and so on. The RF module 220may receive RF wireless signals from the antenna 630, convert thereceived RF wireless signals to baseband signals, which are thenprocessed by the Baseband chip 610, or receive baseband signals from theBaseband chip 610 and convert the received baseband signals to RFwireless signals, which are later transmitted via the antenna 630. TheRF module 220 may also contain multiple hardware devices to performradio frequency conversion. For example, the RF module 220 may comprisea mixer to multiply the baseband signals with a carrier oscillated inthe radio frequency of the wireless communications system, wherein theradio frequency may be 900 MHz, 1800 MHz or 1900 MHz utilized in GSMsystems, or may be 900 MHz, 1900 MHz or 2100 MHz utilized in WCDMAsystems, or others depending on the radio access technology (RAT) inuse. As shown in FIG. 2, the subscriber identity cards 10 and 20 areplugged into two sockets of the MS 110. The MS 110 may further comprisea dual-card controller 640 coupled or connected between the Basebandchip 610 and the subscriber identity cards 10 and 20. The dual-cardcontroller 640 powers the subscriber identity cards 10 and 20 with thesame or different voltage levels according to requirements thereof by apower management integrated chip (PMIC) and a battery, wherein thevoltage level for each subscriber identity card is determined duringinitiation. The Baseband chip 610 reads data from one of the subscriberidentity cards 10 and 20, and writes data to one of the subscriberidentity cards 10 and 20 via the dual-card controller 640. In addition,the dual-card controller 640 selectively transfers clocks, resets,and/or data signals to the subscriber identity cards 10 and 20 accordingto instructions issued by the Baseband chip 610. The Baseband chip 610may support one or more of the GSM/GPRS/EDGE, WCDMA, CDMA 2000, WiMAX,TD-SCDMA, LTE, and TD-LTE technologies. The subscriber identity cards 10and 20 may be any two of the Subscriber Identity Module (SIM) cards,Universal SIM (USIM) cards, Removable User Identity Module (R-UIM), andCDMA Subscriber Identity Module (CSIM) cards, which are corresponding tothe wireless communications technologies supported by the Baseband chip610. The MS 600 can therefore simultaneously camp on two cells providedby either the same network operator or different network operators forthe plugged subscriber identity cards 10 and 20, and operate in stand-bymode using the single RF module 620 and the Baseband chip 610.Alternatively, FIG. 7 shows a block diagram illustrating the hardwarearchitecture of an MS according to another embodiment of the invention.Similar to FIG. 2, the Baseband chip 710 performs baseband signalingprocessing, such as analog to ADC/DAC, gain adjusting,modulation/demodulation, encoding/decoding, and so on. However, theconnections from the MS 700 to the subscriber identity cards 10 and 20are independently handled by two interfaces (I/F) provided in theBaseband chip 710. It is to be understood that the hardware architectureas shown in FIG. 6 or 7 may be modified to include more than twosubscriber identity cards, and the invention cannot be limited thereto.

FIG. 8 is a block diagram illustrating the hardware architecture of anMS coupled with two subscriber identity cards and a single antennaaccording to an embodiment of the invention. The exemplary hardwarearchitecture may be applied to any MS utilizing GSM/GPRS and WCDMAtechnologies. In the exemplary hardware architecture, two Radio AccessTechnology (RAT) modules 810 and 820 share a single antenna 830, andeach RAT module contains at least an RF module and a Baseband chip, tocamp on a cell and operate in stand-by mode, idle mode, or connectedmode. As shown in FIG. 8, the GSM/GPRS Baseband chip 811 is coupled to aGSM/GPRS RF module 812, and the WCDMA Baseband chip 821 is coupled to aWCDMA RF module 822. In addition, when operating in a specific mode,each RAT module interacts with a specific subscriber identity card, suchas (U)SIM A or B. A switching device 840 is coupled between the sharedantenna 830 and multiple Low Noise Amplifiers (LNAs), and connects theantenna 830 to one LNA to allow the RF signals to pass through theconnected LNA. Each LNA amplifies signals in a 2G/3G band received bythe shared antenna 830 and provides the signals to a corresponding RFmodule, wherein the 2G/3G band may be a 900 MHz, 1800 MHz, 1900 MHz, or2100 MHz band, or others. Once one of the Baseband modules attempts toperform a transceiving activity, such as a transmission (TX) or areception (RX) activity, it issues a control signal Ctrl_GSM_band_sel orCtrl_WCDMA_band_sel to direct the switching device 840 to connect theshared antenna 830 to a designated LNA. Note that the GSM/GPRS Basebandchip 811 and the WCDMA Baseband chip 821 are further connected forperforming the coordination operations relating to thesuspension/termination and resumption/restart of data transmission orreception as described above. It is to be understood that the GSM/GPRSmodule 810 and the WCDMA module 820 are given as examples. For thoseskilled in the art, it may be contemplated to use any two of theGSM/GPRS/EDGE, WCDMA, CDMA 2000, WiMAX, TD-SCDMA, LTE, TD-LTE, or otherstechnologies, to implement the RAT modules 810 and 820 in the hardwarearchitecture without departing from the spirit of the invention, and theinvention cannot be limited thereto. It is to be understood that thehardware architecture as shown in FIG. 8 may be modified to include morethan two subscriber identity cards, and the invention cannot be limitedthereto.

A SIM card typically contains user account information, an internationalmobile subscriber identity (IMSI), and a set of SIM application toolkit(SAT) commands. In addition, storage space for phone book contacts isprovided in SIM cards. A micro-processing unit (MCU) of a Baseband chip(referred to as a Baseband MCU hereinafter) may interact with the MCU ofa SIM card (referred to as a SIM MCU hereinafter) to fetch data or SATcommands from the plugged SIM card. An MS is immediately programmedafter plugging in the SIM card. SIM cards may also be programmed todisplay custom menus for personalized services. A SIM card may furtherstore a Home Public-Land-Mobile-Network (HPLMN) code to indicate anassociated network operator, wherein the HPLMN code contains a MobileCountry Code (MCC) followed by a Mobile Network code. To furtherclarify, an IMSI is a unique number associated with a global system formobile communication (GSM) or a universal mobile telecommunicationssystem (UMTS) network user. An IMSI may be sent by an MS to a GSM orUMTS network to acquire other detailed information of the network userin the Home Location Register (HLR) or to acquire the locally copieddetailed information of the network user in the Visitor LocationRegister (VLR). Typically, an IMSI is 15 digits long or shorter (forexample, the MTN South Africa's IMSIs are 14 digits long). The first 3digits are the Mobile Country Code (MCC), and are followed by the MobileNetwork Code (MNC), either 2 digits (European standard) or 3 digits(North American standard). The remaining digits are the mobilesubscriber identification number (MSIN) for a GSM or UMTS network user.

A USIM card is inserted in an MS for UMTS (also called 3G) telephonycommunication. A USIM card stores user account information, IMSI,authentication information and a set of USIM Application Toolkit (USAT)commands, and provides storage space for text messages and phone bookcontacts. A USIM card may further store a HomePublic-Land-Mobile-Network (HPLMN) code to indicate an associatednetwork operator. A Baseband MCU may interact with an MCU of a USIM card(referred to as a USIM MCU hereinafter) to fetch data or USAT commandsfrom the plugged USIM card. Note that the phone book on the USIM cardhas been greatly enhanced from that of the SIM card. For authenticationpurposes, the USIM card may store a long-term preshared secret key K,which is shared with the Authentication Center (AuC) in the network. TheUSIM MCU may verify a sequence number that must be within a range usinga window mechanism to avoid replay attacks, and is in charge ofgenerating the session keys CK and IK to be used in the confidentialityand integrity algorithms of the KASUMI (also termed A5/3) block cipherin UMTS. An MS is immediately programmed after plugging in the USIMcard. In addition, an R-UIM or CSIM card is developed for a CDMA MS thatis equivalent to the GSM SIM and 3G USIM, except that it is capable ofworking in CDMA networks. The R-UIM or CSIM card is physicallycompatible with the GSM SIM card, and provides a similar securitymechanism for CDMA networks and network users.

FIG. 9 is a block diagram illustrating the software architecture of anMS according to an embodiment of the invention. The exemplary softwarearchitecture may contain protocol stack handlers 910 and 920, and anapplication layer 930. The protocol stack handler 910, when executed bya processing unit or a Baseband MCU, is configured to communicate withthe service network 120 with a first subscriber identity card (e.g. thesubscriber identity card 10), while the protocol stack handler 920, whenexecuted by a processing unit or a Baseband MCU, is configured tocommunicate with the service network 130 with a second subscriberidentity card (e.g. the subscriber identity card 20). The applicationlayer 930 may contain program logics for providing Man-Machine Interface(MMI). The MMI is the means by which people interact with the MS, andthe MMI may contain screen menus and icons, keyboard, shortcuts, commandlanguage, and online help, as well as physical input devices, such asbuttons, touch screen, and keypad. By the input devices of the MMI,users may manually touch, press, click, or move the input devices tooperate the MS for making or answering a phone call, texting, sending,or viewing short messages, multimedia messages, e-mails or instantmessages, surfing the Internet, or others. Specifically, the applicationlayer 930 may receive a user request for making an MO call with thefirst subscriber identity card, while the protocol stack handler 920 isperforming a background packet-switched (PS) data service on-line, suchas a push e-mail, an instant messaging (IM) service, or others, which isrun in background and kept on-line with a corresponding server, with thesecond subscriber identity card. For the push e-mail service, e-mailmessages that have been received by a server mail system may betransmitted automatically to the MS as data packets via a cellularnetwork to keep mobile user up-to-date. The IM service is used forreal-time text-based communications between two or more participantsover the Internet, a cellular network, or the combination.Correspondingly, the application layer 930 may contain an e-mail clientfacilitating a user to edit, browse, or send e-mail messages, and/or anIM client facilitating a user to edit, browse, or send IM messages. Whenreceiving the user request for MO call, the application layer 930 mayrequest the protocol stack handler 910 to make the MO call with thefirst subscriber identity card. After that, the protocol stack handler910 requests the protocol stack handler 920 to suspend or terminate thebackground PS data service. As soon as the background PS data service issuspended or terminated by the protocol stack handler 920, the protocolstack handler 910 continues to perform the MO call with the firstsubscriber identity card. Later, when the MO call is finished, theprotocol stack handler 910 may inform the protocol stack handler 920 toresume or restart the background PS data service. In one embodiment,when the MO call is finished, the protocol stack handler 910 may checkwhether the background PS data service is suspended or terminated due tothe made MO call. If so, the protocol stack handler 910 then informs theprotocol stack handler 920 to resume or restart the background PS dataservice. For example, the protocol stack handler 910 may use a flag ormarker to note the above condition, e.g. the default value of the flagor marker is set to “OFF”, the value of the flag or marker is set to“ON” when the background PS data service is suspended or terminated foran MO call, and the value of the flag or marker is set to “OFF” when theMO call is finished.

FIG. 10 is a flow chart illustrating an embodiment of the method forcoordinating the operations between the protocol stack handlers 910 and920 with respect to the software architecture shown in FIG. 9.Initially, the protocol stack handler 920 is in the in-service statewhere it occupies the single radio resource, such as a single antenna orsingle RF module, to support a background PS data service on-line, suchas push e-mail, IM, or others, with the second subscriber identity card(step S1010). Next, the application layer 930 receives a user requestfor making an MO call, such as an MO voice or data call, or fortransferring an MO short message or multimedia message, with the firstsubscriber identity card, and then issues an MO attempt to the protocolstack handler 910 (step S1020). The protocol stack handler 910 requeststhe protocol stack handler 920 to suspend or terminate the background PSdata service corresponding to the second subscriber identity card inresponse to the user request (step S1030). In one embodiment, whenreceiving the user request, the application layer 930 may firstdetermines whether an MO call has higher priority than a background PSdata service. If so, the application layer 930 proceeds to issue an MOattempt to the protocol stack handler 910. In another embodiment, theservice associated with the first subscriber identity card may bespecified to have higher priority than the service associated with thesecond subscriber identity cards, or the other way around. For example,a subscriber identity card mainly used for CS services may have higherpriority than another subscriber identity card mainly used for PS dataservices, or users may set one preferred subscriber identity card with ahigher priority among a plurality of subscriber identity cards. Inaddition, the application layer 930 may further request user'spermission once detecting that the background PS data service is kepton-line, and only request the protocol stack handler 910 for issuing anMO attempt if the permission is granted. Note that the protocol stackhandler 920 may further informs the service network 130 that thebackground PS data service is being suspended or terminated, beforesuspending or terminating the background PS data service.

Subsequently, when receiving the request from the protocol stack handler910, the protocol stack handler 920 suspends or terminates thebackground PS data service and then enters the no-service state (stepS1040). Upon entering the no-service state, the protocol stack handler920 further acknowledges the request from the protocol stack handler 910(step S1050). To enter the no-service state, the protocol stack handler920 may remove scheduled channel tasks, such as listening to PPCH, PCHor others, causing the MS to receive no packet paging messages from thecamped on cell, and hinder any PRACH, RACH, PACCH, or similar uplinkchannel allocation for the second subscriber identity card.Alternatively, the protocol stack handler 920 may request the radioresource hardware, such as particular circuits of the Baseband chip tocontrol the RF module, for suspending of the scheduled channel tasks, orfor detaching the attached data service, such as GPRS. It is to beunderstood that, when the radio resource is occupied by the backgroundPS data service for the second subscriber identity card, the protocolstack handler 910 no longer transceives data with the first subscriberidentity card. Thus, after receiving the acknowledgement from theprotocol stack handler 920, the protocol stack handler 910 requests theradio resource hardware for regaining service for the first subscriberidentity card (step S1060).

One way to regain the service is that the protocol stack handler 910 mayattempt to camp on the last serving cell before the start of thebackground PS data service. The last serving cell means the cell whichhad been camped on with the first subscriber identity card but beenhanged because the single radio source is occupied for the background PSdata service with the second subscriber identity card. The protocolstack handler 910 may read information regarding the last serving cell,which was recorded before the start of the background PS data service,and accordingly try to camp on it. Another way to regain the service isthat the protocol stack handler 910 may find out a best cell in apre-stored cell list, which was recorded before the start of thebackground PS data service, and attempt to camp on the found best cell,where the best cell means in which the measured signal has the bestquality. If the last serving cell or all cells of the pre-stored celllist cannot be successfully camped on, the protocol stack handler 910may direct the radio resource hardware to perform a Public Land MobileNetwork (PLMN) search procedure to find out a suitable cell to be campedon. The PLMN search procedure for the WCDMA system is described below asan example. To begin, the WCDMA Baseband chip may instruct the WCDMA RFmodule to perform power scan to find out one or more cells with thebetter signal quality. Based on the power scan results, a cell searchprocedure may be performed for the cell with the best signal quality,containing steps of slot synchronization, frame synchronization andcode-group identification, and scrambling-code identification. In thestep of slot synchronization, the MS uses the primary synchronizationcode of synchronization Channel (SCH) to acquire slot synchronization tothe cell. In the step of frame synchronization and code-groupidentification, the MS employs the secondary synchronization code of SCHto find frame synchronization and identify the code group of the cellfound in the previous step. In the step of scrambling-codeidentification, the MS determines the exact primary scrambling code usedby the cell. The primary scrambling code is typically identified throughsymbol-by-symbol correlation over the common pilot channel (CPICH) withall codes within the code group identified in the previous step. Afterthe primary scrambling code is identified, the primary common controlphysical channel (CCPCH) may be detected and the cell-specific broadcastchannel (BCH) information may be read. After completely collecting andstoring information regarding the exact channel configuration andneighboring cells in memory or a storage device, the WCDMA moduleperforms a location update procedure to inform the cellular network ofits location. The PLMN search procedure for the GSM/GPRS system isdescribed below as another example. The MS starts to perform power scanto find out proper cells to camp on. During power scan, the GSM/GPRSBaseband chip may instruct the GSM/GPRS RF module to perform signallevel measurements on frequencies of the current network. After findingpotential candidates based on the received signal level RXLREV (that is,completion of the power scan), each carrier is investigated by theGSM/GPRS Baseband chip for the presence of a frequency correctionchannel (FCCH), beginning with the strongest signal. A FCCH burst (FCB)is an all-zero sequence that produces a fixed tone enabling the GSM/GPRSRF module to lock its local oscillator to the base station clock. Itspresence identifies the carrier as a BCCH carrier for synchronization.The MS then uses a synchronization burst (SB) of the synchronizationchannel (SCH) following the FCCH burst and having a long trainingsequence to fine tune the frequency correction and time synchronization.The GSM/GPRS Baseband chip obtains and stores the exact channelconfiguration of the selected cell from the BCCH data as well as thefrequencies of the neighboring cells. After completely collecting andstoring information regarding the exact channel configuration andneighboring cells in memory or a storage device, the GSM/GPRS moduleperforms a location update procedure through a traffic channel (TCH) toinform the cellular network of its location.

Subsequent to step 1060, the protocol stack handler 910 handles controlsignaling and data transceiving for the MO call via the radio resourcehardware until the MO traffic is finished (step S1070). The MO trafficmay refer to a voice call as shown in FIG. 2, a short messagetransmission, a multimedia message transmission, or data packettransceiving (may be utilized to make a data call) as shown in FIG. 4.The MO traffic may be finished when the user gets off the phone via theMMI provided by the application layer 930, or when the MO short messageor multimedia message is successfully transferred. Alternatively, the MOtraffic may be finished when detecting that the corresponding node isbusy or rejects the voice or data call, or when the transfer of the MOshort message or multimedia message is failed. When the MO traffic isfinished, the protocol stack handler 910 informs the protocol stackhandler 920 that the suspended or terminated background PS data servicemay be resumed or restarted (step S1080). Then, the protocol stackhandler 920 enters in-service state to resume or restart the suspendedor terminated background PS data service (step S1090). To enter thein-service state, the protocol stack handler 920 may re-schedule channeltasks, such as such as listening to PPCH, PCH or others, causing the MSto receive packet paging messages and allow PRACH, RACH, PACCH, orsimilar channel allocation. Alternatively, the protocol stack handler920 may request the radio resource hardware for resuming of thescheduled channel tasks, or for attaching data service, such as GPRS asshown in FIG. 3. It is to be understood that the suspended background PSdata service may be resumed without any information loss when thesuspending time period is shorter than a tolerable time. Or, during thesuspending time period, no data is required to receive by thecorresponding application, such as e-mail client, IM client, or others.Note that, in the resumption or restart of the background PS dataservice, the protocol stack handler 920 may need to regain the serviceof the radio resource hardware when the previously camped on cell is nolonger available. Ways to regain the service may refer to that performedby the protocol stack handler 910 as stated above.

FIG. 11 is a message sequence chart illustrating the method forcoordinating the operations between the protocol stack handlers 910 and920 according to the embodiment of FIG. 10. In this embodiment, theprotocol stack handler 920 corresponds to a USIM card conform to theWCDMA standard and initially configured to operate in the in-servicestate for performing an IM service with the service network 130 via asingle radio resource (step S1110). Alternatively, the protocol stackhandler 920 may support another background PS data service instead, suchas the MMS service or push-email service. Or, the protocol stack handler920 may support two or more background PS data services with the USIMcard. Meanwhile, the application layer 930 receives a user request formaking an MO call with a SIM card corresponding to the protocol stackhandler 910 (step S1120). Then, the application layer 930 issues an MOattempt to the protocol stack handler 910 (step S1130). Assuming thatthe MO call has higher priority than the IM service, the protocol stackhandler 910 requests the protocol stack handler 920 to suspend orterminate the IM service (step S1140). When receiving the request forservice suspension or termination, the protocol stack handler 920suspends or terminates the IM service, and then enters the no-servicestate (step S1150). As soon as the IM service is suspended orterminated, the radio resource is released and the protocol stackhandler 920 informs the protocol stack handler 910 that the IM servicehas been suspended or terminated (step 1160). When being informed by theprotocol stack handler 920, the protocol stack handler 910 proceeds tomake the MO call with the SIM card (step S1170). After the MO traffic isfinished, the protocol stack handler 910 informs the protocol stackhandler 920 that the suspended or terminated IM service may be resumedor restarted (step S1180). Accordingly, the protocol stack handler 920enters the in-service state to resume or restart the IM service whenbeing informed by the protocol stack handler 910 (step S1190).

FIG. 12 is a flow chart illustrating another embodiment of the methodfor coordinating the operations between the protocol stack handlers 910and 920 with respect to the software architecture shown in FIG. 9.Similar to the steps 1010 and 1020 in FIG. 10, the application layer 930receives a user request for making an MO call with the first subscriberidentity card and issues an MO attempt to the protocol stack handler910, while the protocol stack handler 920 is in the in-service state forperforming a background PS data service with the second subscriberidentity card (step S1205). The protocol stack handler 910 stores theinformation concerning the MO attempt in a memory or storage device whenreceiving the MO attempt (step 1210). When in the in-service state forsupporting the background PS data service, the protocol stack handler920 periodically inspects if the protocol stack handler 910 has any MOattempt on-hold (step S1215). This may be achieved by checking whetherthe information concerning the MO attempt is present in the memory orstorage device, or by polling the protocol stack handler 910. Subsequentto step S1215, if not, the protocol stack handler 920 maintains thebackground PS data service until the next check point (step S1220). Ifso, the protocol stack handler 920 suspends or terminates the backgroundPS data service, and enters the no-service state (step S1225). Detaileddescription regarding the operations in the no-service state may referto the above description relating to FIG. 10. After entering theno-service state, the protocol stack handler 920 informs the protocolstack handler 910 that the radio resource has been released (stepS1230). Then, the protocol stack handler 910 requests the radio resourcehardware for regaining service for the first subscriber identity card(step S1235), and handles control signaling and data transceiving untilthe MO traffic is finished (step S1240), as mentioned above in FIG. 10.When the MO traffic is finished, the protocol stack handler 910 informsthe protocol stack handler 920 that the suspended or terminatedbackground PS data service can be resumed or restarted (step S1245),enabling the protocol stack handler 920 to enter the in-service state(step S1250).

In another embodiment, instead of suspending or terminating thebackground PS data service, the coordination of operations between theprotocol stack handlers 910 and 920 may be designed differently, suchthat the protocol stack handler 910 redirects the MO attempt to theprotocol stack handler 920 when receiving the request from theapplication layer 930. Next, the protocol stack handler 920 makes the MOcall with the second subscriber identity card. That is, the MO call ismade using the network resources assigned by the service network 130(connected with the protocol stack handler 920) instead of the servicenetwork 120 (connected with the protocol stack handler 910). Since thecharges of the MO call will be billed to the second subscriber identitycard instead of the first subscriber identity card, it may be preferredto advise the user before the redirection. For instance, the user mayprefer to have the MO call made with the first subscriber identity cardwhen the monthly rate configured for the first subscriber identity cardhas not yet been reached, or the user may prefer to make the MO callwith the first subscriber identity card if the MO attempt relates to avoice call service and the first subscriber identity card provides voicecall services with lower costs. Therefore, before redirecting the MOattempt to the protocol stack handler 920, the protocol stack handler910 may request, via the application layer 930, permission from the userto do so, and the redirection of the MO attempt is only performed whenthe permission is granted.

FIG. 13 is a block diagram illustrating the software architecture of anMS according to another embodiment of the invention. Similar to FIG. 9,the exemplary software architecture also contains the protocol stackhandlers 910 and 920, and the application layer 930. Additionally, aresource reservation arbitrator (RRSVA) 940 is included, which solvesconflicts between the protocol stack handlers 910 and 920 and arbitrateswhich one of the protocol stack handlers 910 and 920 may occupy theradio resource hardware at a given time. The RRSVA 940 may beimplemented in program code and, when the program code is loaded andexecuted by the processing unit or MCU, grants or rejects radio resourcerequests issued by any of the protocol stack handlers 910 and 920 interms of predefined rules with the priorities of the requested traffics.For example, a CS service traffic, such as MO traffic, may have higherpriority than a PS service traffic, such as traffic for push e-mail, IM,or others. Alternatively, the traffic requested by a specific protocolstack handler may be predefined to have higher priority than the trafficrequested by other protocol stack handlers.

Accompanying with the software architecture of FIG. 13, a flow chart ofa method for coordinating the operations between the protocol stackhandlers 910 and 920 is illustrated in FIG. 14. Initially, the protocolstack handler 920 occupies the single radio resource to support thebackground PS data service on-line, such as push e-mail, IM, or others,with the second subscriber identity card, after receiving a grant fromthe RRSVA 940 for the forthcoming background PS data service. Aftergranting the background PS data service request, the RRSVA 940 stores ina memory or storage device the information regarding that the radioresource hardware is occupied by the protocol stack handler 920 for thebackground PS data service. When the background PS data service is kepton-line, the application layer 930 may receive a user request for makingan MO call, such as an MO voice or data call, or transfer an MO short ormultimedia message with the first subscriber identity card, and then,issue an MO attempt to the protocol stack handler 910 (step 1405). Afterthat, the protocol stack handler 910 requests the RRSVA 940 for grantingof the MO traffic corresponding to the first subscriber identity card(step S1410). The RRSVA 940 then requests the protocol stack handler 920to suspend or terminate of the background PS data service for the MOcall has higher priority than the background PS data service in terms ofa predefined rule (step S1415). After receiving the request from theRRSVA 940, the protocol stack handler 920 enters the no-service state(step S1420). Regarding the possible ways to enter the no-service state,reference may be made to the relevant description of FIG. 10. Aftersuccessfully entering the no-service state, the protocol stack handler920 informs the RRSVA 940 about the completion of the suspending orterminating of the background PS data service (step S1425). The RRSVA940 stores in a memory or storage device the information regarding thatthe radio resource hardware is occupied by the protocol stack handler910 for the MO call when being informed by the protocol stack handler920, and then grants the request of the MO call from the protocol stackhandler 910 (step S1430).

After receiving the grant, the protocol stack handler 910 requests theradio resource hardware for regaining service for the first subscriberidentity card (step S1435). Details for regaining service, please referto the relevant description of FIG. 10, and simply described herein forbrevity. When the service is regained, the protocol stack handler 910handles control signaling and data transceiving via the radio resourcehardware, with the first subscriber identity card, until the MO trafficis finished (step S1440). The MO traffic may be a voice call as shown inFIG. 2, a short message transmission, a multimedia message transmission,or data packet transceiving (may be utilized to make a data call) asshown in FIG. 4. Ways of carrying out the MO traffic may refer to therelevant description of FIG. 10. When the MO traffic is finished, theprotocol stack handler 910 informs the RRSVA 940 about the finish of theMO call (step S1445). The RRSVA 940 subsequently informs the protocolstack handler 920 that the suspended or terminated background PS dataservice can be resumed or restarted (step S1450). Accordingly, theprotocol stack handler 920 enters the in-service state to resume orrestart the suspended or terminated background PS data service (stepS1455). Details for entering the in-service state may refer to therelevant description of FIG. 10, and simply described herein forbrevity.

FIG. 15 is a message sequence chart illustrating the coordination of theoperations between the protocol handlers 910 and 920 according to theembodiment of FIG. 14. In this embodiment, the protocol stack handler920 corresponds to a USIM card conform to the WCDMA standard andperforms a background PS data service with the service network 130 viathe single radio resource with the USIM card (step S1505), while theprotocol stack handler 910 corresponds to a SIM card conform to theGSM/GPRS standard and capable of communicating with the service network120 with the SIM card. At first, the application layer 930 receives auser request for making an MO call with the SIM card (step S1510). Inresponse to the user request, the application layer 930 issues an MOattempt to the protocol stack handler 910 (step S1515). When receivingthe MO attempt from the application layer 930, the protocol stackhandler 910 requests the RRSVA 940 for granting of the MO trafficcorresponding to the SIM card (step S1520). The RRSVA 940 arbitrateswhich one of the protocol stack handlers 910 and 910 can occupy thesingle radio resource to perform the respective service traffic (stepS1525). Assuming that the MO traffic has higher priority than thebackground PS data service traffic, the RRSVA 940 requests the protocolstack handler 920 to suspend or terminate the MMS service (step S1530).When receiving the request for service suspension or termination, theprotocol stack handler 920 enters the no-service state in which thebackground PS data service is suspended or terminated (step S1535). Thatis, the single radio resource is released due to that the protocol stackhandler 920 no longer occupies the single radio resource for thebackground PS data service. The protocol stack handler 920 informs theRRVSA 940 about the completion of the service suspension or termination(step 1540). Subsequently, the RRSVA 940 grants the request of the MOtraffic issued by the protocol stack handler 910 (step S1545). Afterreceiving the grant from RRSVA 940, the protocol stack handler 910requests the radio resource hardware for regaining service for the firstsubscriber identity card (step S1550). After that, the protocol stackhandler 910 handles control signaling and data transceiving via theradio resource hardware, with the SIM card, until the MO traffic isfinished (step S1555). Later, when the MO traffic is finished, theprotocol stack handler 910 informs the RRSVA 940 that the requested MOtraffic is finish (step S1560). When being informed about the MO trafficbeing finished, the RRSVA 940 determines that the MMS service has beenpreviously suspended or terminated due to the MO traffic and therefore,informs the protocol stack handler 920 that the suspended or terminatedbackground PS data service can be resumed or restarted (step S1565).Accordingly, the protocol stack handler 920 enters the in-service stateto resume or restart the suspended or terminated background PS dataservice (step S1570).

FIG. 16 is a block diagram illustrating the software architecture of anMS according to yet another embodiment of the invention. Similar to FIG.12, the exemplary software architecture also contains the protocol stackhandlers 910 and 920, the application layer 930, and the RRSVA 940.However, the application layer 930 coordinates the operations betweenthe RRSVA 940 and the protocol stack handlers 910 and 920 to completethe MO call requested by users. Accompanying with the softwarearchitecture of FIG. 16, a flow chart of a method for coordinating theoperations between the protocol stack handlers 910 and 920 isillustrated in FIG. 17. When the background PS data service is kepton-line, the application layer 930 receives via the MMI a user requestfor making an MO call, such as an MO voice or data call, or transfer anMO short or multimedia message with the first subscriber identity card(step S1705), and then, requests the RRSVA 940 for granting of the MOtraffic corresponding to the first subscriber identity card (stepS1710). The RRSVA 940 then requests the protocol stack handler 920 tosuspend or terminate of the background PS data service (step S1715).After receiving the request from the RRSVA 940, the protocol stackhandler 920 enters the no-service state (step S1720). Regarding the waysto enter the no-service state, reference may be made to the relevantdescription of FIG. 10. After successfully entering the no-servicestate, the protocol stack handler 920 informs the RRSVA 940 about thecompletion of the suspending or terminating of the background PS dataservice (step S1725). Note that the RRSVA 940 maintains informationindicating which protocol stack handler currently occupies the singleradio resource for a particular purpose, as discussed above.Specifically, the RRSVA 940 stores in a memory or storage device theinformation regarding that the radio resource hardware is occupied bythe protocol stack handler 910 for the MO call when being informed bythe protocol stack handler 920, and then grants the request of the MOcall from the application layer 930 (step S1730).

After the RRSVA 940 grants the request, the application layer 930requests the protocol stack handler 910 for making the MO call (stepS1735). Note that, the application layer 930 may further find outcurrently executed client applications, such as e-mail client, IM clientor others, and close them from use. After that, as discussed above, theprotocol stack handler 910 requests the radio resource hardware forregaining service for the first subscriber identity card (step S1740),and then controls signaling and data transceiving via the radio resourcehardware until the MO traffic is finished (step S1745). After receivinga notification indicating that the requested MO traffic is finished fromthe protocol stack handler 910 (step S1750), the application layer 930forwards the notification to the RRSVA 940 (step S1755), enabling theRRSVA 940 to inform the protocol stack handler 920 that the suspended orterminated background PS data service may be resumed or restarted (stepS1760). Accordingly, as discussed above, the protocol stack handler 920enters the in-service state to resume or restart the suspended orterminated background PS data service (step S1765). Also, the RRSVA 940may modify the maintained information correspondingly. The applicationlayer 930 may further restarts the client applications which were closedto bring the background PS data service back to on-line if required.

FIG. 18 is a message sequence chart illustrating the coordination of theoperations between the protocol handlers 910 and 920 according to theembodiment of FIG. 17. In this embodiment, the protocol stack handler920 corresponds to a USIM card conform to the WCDMA standard andperforms an background PS data service with the service network 130 viathe single radio resource with the USIM card (step S1805), while theprotocol stack handler 910 corresponds to a SIM card conform to theGSM/GPRS standard and capable of communicating with the service network120 with the SIM card. At first, the application layer 930 receives viathe MMI a user request for making an MO call with the SIM card (stepS1810). In response to the user request, the application layer 930requests the RRSVA 940 for granting of the MO traffic corresponding tothe first subscriber identity card (step S1815). Subsequently, the RRSVA940 arbitrates which one of the protocol stack handlers 910 and 910 canoccupy the single radio resource to perform the respective servicetraffic (step S1820). Assuming that the MO traffic has higher prioritythan the background PS data service traffic, the RRSVA 940 requests theprotocol stack handler 920 to suspend or terminate the background PSdata service (step S1825). When receiving the request for servicesuspension or termination, the protocol stack handler 920 enters theno-service state in which the background PS data service is suspended orterminated (step S1830). That is, the single radio resource is releaseddue to that the protocol stack handler 920 no longer occupies the singleradio resource for the background PS data service. Then, the protocolstack handler 920 informs the RRVSA 940 about the completion of theservice suspension or termination (step S1835). After that, the RRSVA940 grants the request of the MO traffic issued by the application layer930 (step S1840). After receiving the grant from RRSVA 940, theapplication layer 930 requests the protocol stack handler 910 for makingthe MO call (step S1845). The protocol stack handler 910 requests theradio resource hardware for regaining service for the first subscriberidentity card (step S1850). With the service regained, the protocolstack handler 910 handles control signaling and data transceiving viathe radio resource hardware, with the SIM card, until the MO traffic isfinished (step S1855). Later, when the MO traffic is finished, theprotocol stack handler 910 informs the application layer 930 that therequested MO traffic is finish (step S1860), and the application layer930 forwards the information to the RRSVA 940 (step S1865). Wheninformed about the MO traffic being finished, the RRSVA 940 determinesthat the background PS data service has been previously suspended orterminated due to the MO traffic and therefore, informs the protocolstack handler 920 that the suspended or terminated background PS dataservice can be resumed or restarted (step S1870). Accordingly, theprotocol stack handler 920 enters the in-service state to resume orrestart the suspended or terminated background PS data service (stepS1875).

In another embodiment, in the methods of FIG. 14 and FIG. 17, the RRSVA940 may redirect the MO attempt to the protocol stack handler 920instead of the protocol stack handler 910 when receiving the request forgranting of the MO traffic. Since the charges of the MO call will bebilled to the second subscriber identity card instead of the firstsubscriber identity card, it may be preferred to advise the user beforethe redirection. For instance, the user may prefer to have the MO callmade with the first subscriber identity card when the monthly rateconfigured for the first subscriber identity card has not yet beenreached, or the user may prefer to perform the MO call with the firstsubscriber identity card if the MO call relates to a voice call serviceand the first subscriber identity card provides voice call services withlower costs. Therefore, before redirecting the MO call to the protocolstack handler 920, the RRSVA 940 may request, via the application layer930, permission from the user to do so, and the redirection of the MOcall is only performed when the permission is granted.

While the invention has been described by way of example and in terms ofpreferred embodiment, it is to be understood that the invention is notlimited thereto. Those who are skilled in this technology can still makevarious alterations and modifications without departing from the scopeand spirit of this invention. For example, the software architectures ofFIGS. 9, 16, and 13 may each be implemented in program code stored in amachine-readable storage medium, such as a magnetic tape, semiconductor,magnetic disk, optical disc (e.g., CD-ROM, DVD-ROM, etc.), or others. AWeb server may store the software architectures of FIGS. 9, 16, and 13in a machine-readable storage medium, which can be downloaded by aclient computer through the Internet. When loaded and executed by theprocessing unit or MCU, the program code may perform the methods ofFIGS. 10 and 12, 14, or 17, respectively corresponding to the softwarearchitectures of FIGS. 9, 16, and 13. Although the embodiments describedabove employ the GSM/GPRS and WCDMA based technologies, the invention isnot limited thereto. The embodiments may also be applied to othercellular network technologies, such as CDMA 2000, and TD-SCDMA, WiMAX,LTE, and TD-LTE technologies. Therefore, the scope of the presentinvention shall be defined and protected by the following claims andtheir equivalents.

Use of ordinal terms such as “first”, “second”, “third”, etc., in theclaims to modify a claim element does not by itself connote anypriority, precedence, or order of one claim element over another or thetemporal order in which acts of a method are performed, but are usedmerely as labels to distinguish one claim element having a certain namefrom another element having a same name (but for use of the ordinalterm) to distinguish the claim elements.

What is claimed is:
 1. A wireless communications device, comprising: aradio frequency (RF) module; and a baseband chip configured to initiatea mobile originated (MO) call through the RF module with a firstsubscriber identity card when the RF module is occupied by performing apacket switched (PS) data service with a second subscriber identitycard, arbitrate a first protocol stack handler to suspend or terminatethe PS data service associated with the second subscriber identity cardin response to initiating the MO call associated with the firstsubscriber identity card, and arbitrate a second protocol stack handlerto make the MO call associated with the first subscriber identity cardwhen the PS data service associated with the second subscriber identitycard is suspended or terminated, wherein the baseband chip furtherdetermines whether the MO call has a higher priority than the PS dataservice and the arbitration of the first protocol stack handler tosuspend or terminate the PS data service is performed when the MO callhas a higher priority than the PS data service.
 2. The wirelesscommunications device of claim 1, wherein the baseband chip furtherarbitrates the first protocol stack handler to resume or restart the PSdata service associated with the second subscriber identity card whenthe MO call is finished.
 3. The wireless communications device of claim2, wherein the baseband chip further arbitrates the first protocol stackhandler to regain service for the second subscriber identity cardsubsequent to the finishing of the MO call and prior to the resuming orrestarting of the PS data service.
 4. The wireless communications deviceof claim 2, wherein the baseband chip further arbitrates the firstprotocol stack handler to inform a service network associated with thePS data service about the suspension or termination of the PS dataservice, prior to suspending or terminating the PS data service, and toinform the service network about the resumption or restart of the PSdata service prior to resuming or restarting the PS data service.
 5. Thewireless communications device of claim 1, wherein the baseband chipfurther requests permission to a user via a man-machine interface (MMI)to suspend or terminate the PS data service, and the arbitration of thefirst protocol stack handler to suspend or terminate PS data service isperformed when the permission is granted by the user via the MIMI. 6.The wireless communications device of claim 1, wherein the baseband chipfurther arbitrates the second protocol stack handler to regain servicefor the first subscriber identity card subsequent to the arbitrating thefirst protocol stack handler to suspend or terminate the PS data serviceand prior to arbitrating the second protocol stack handler to make theMO call.
 7. The wireless communications device of claim 1, wherein thebaseband chip further arbitrates the second protocol stack handler tocamp on the last serving cell based on information, which was recordedbefore start of the PS data service, to regain service for the firstsubscriber identity card.
 8. The wireless communications device of claim1, wherein the baseband chip further arbitrates the second protocolstack handler to find out a best cell from a cell list, which wasrecorded before start of the PS data service, and camp on the found bestcell to regain service for the first subscriber identity card.
 9. Thewireless communications device of claim 1, wherein the baseband chipfurther arbitrates the second protocol stack handler to perform a PublicLand Mobile Network search procedure to camp on a suitable cell toregain service for the first subscriber identity card.
 10. The wirelesscommunications device of claim 1, wherein the PS data service is a pushe-mail or an instant messaging service, which is run in background andkept on-line with a corresponding server.
 11. The wirelesscommunications device of claim 1, wherein the baseband chip furtherarbitrates the first protocol stack handler to suspend or removescheduled channel tasks for suspending or terminating the PS dataservice, causing to receive no packet paging messages with the secondsubscriber identity card, and to hinder uplink channel allocation forthe second subscriber identity card.
 12. The wireless communicationsdevice of claim 1, wherein the baseband chip further arbitrates thefirst protocol stack handler to detach an attached data service forsuspending or terminating the PS data service.
 13. A method forcoordinating operations between circuit switched (CS) and packetswitched (PS) services with different subscriber identity cards in awireless communications device, comprising: initiating a MobileOriginated (MO) call through a RF module from the wirelesscommunications device with a first subscriber identity card when the RFmodule is occupied by performing a PS data service with a secondsubscriber identity card; determining whether the MO call has a higherpriority than the PS data service; arbitrating a first protocol stackhandler to suspend or terminate the PS data service associated with thesecond subscriber identity card in response to initiating the MO callassociated with the first subscriber identity card when the MO call hasa higher priority than the PS data service; and arbitrating a secondprotocol stack handler to make the MO call associated with the firstsubscriber identity card when the PS data service associated with thesecond subscriber identity card is suspended or terminated.
 14. Themethod of claim 13, further comprising arbitrating the second protocolstack handler to regain service for the first subscriber identity cardsubsequent to arbitrating the first protocol stack handler to suspend orterminate the PS data service and prior to arbitrating the secondprotocol stack handler to make the MO call.
 15. The method of claim 14,wherein the regaining step further comprises: finding out a best cellfrom a cell list, which was recorded before start of the PS dataservice; and camping on the found best cell to regain service.
 16. Themethod of claim 14, wherein the regaining step further comprisesperforming a Public Land Mobile Network search procedure to camp on asuitable cell to regain service.
 17. The method of claim 14, furthercomprising requesting permission to a user to suspend or terminate thePS data service before arbitrating the first protocol stack handler forthe suspending or terminating step, wherein the arbitration of the firstprotocol stack handler for the suspending or terminating step isperformed when the permission is granted.
 18. A non-transitorymachine-readable storage medium comprising program code, which, whenexecuted, causes a wireless communications device to perform a methodfor coordinating operations between circuit switched (CS) and packetswitched (PS) services with different subscriber identity cards in awireless communications device, the method comprising: initiating aMobile Originated (MO) call through a RF module from the wirelesscommunications device with a first subscriber identity card when the RFmodule is occupied by performing a PS data service with a secondsubscriber identity card; determining whether the MO call has a higherpriority than the PS data service; arbitrating a first protocol stackhandler to suspend or terminate the PS data service associated with thesecond subscriber identity card in response to initiating the MO callassociated with the first subscriber identity card when the MO call hasa higher priority than the PS data service; and arbitrating a secondprotocol stack handler to make the MO call associated with the firstsubscriber identity card when the PS data service associated with thesecond subscriber identity card is suspended or terminated.
 19. Awireless communications device, comprising: a radio frequency (RF)module; and a baseband chip configured to initiate a mobile originated(MO) call through the RF module from the wireless communications devicewith a first subscriber identity card when the RF module is occupied byperforming a packet switched (PS) data service with a second subscriberidentity card, redirect the MO call to the second subscriber identitycard, and make the MO call with the second subscriber identity card;wherein the baseband chip further determines whether the MO call has ahigher priority than the PS data service and the redirection of the MOcall to the second subscriber identity card is performed when the MOcall has a higher priority than the PS data service.
 20. The wirelesscommunications device of claim 19, wherein the baseband chip is furtherconfigured to request a permission to a user to redirect the MO call tothe second subscriber identity card, and make the MO call with thesecond subscriber identity card when the permission is granted by theuser.